The conventional process for installing an electrical device, e.g., a light switch, outlet, or telephone/computer jack, in a junction box involves mounting the junction box on a wall stud before the drywall in installed, mounting the electrical device on a box cover plate (often referred to as a “mud ring”), connecting the wiring of the device to the wiring in the junction box, securing the box cover plate and the device to the junction box, and attaching a cover plate to the electrical device to cover and protect the assembly. The drywall (or other type of wall) is installed at a later time, sometimes days or even weeks or months later. An opening is cut in the drywall to reveal the electrical device.
The above process has drawbacks. For example, if the thickness of the drywall is changed after installation of the electrical device, the mud rings must be replaced. Further, the electrical device must be installed at an early stage of the process, even though there may be a substantial delay before the installation process is finally finished. The purchase of materials, including expensive electrical devices, long before they are actually ready for use is undesirable from the standpoint of cash flow, especially where a job requires many such devices. Also, there may be design changes after the dry wall is installed, such as a change in the type of finish cover plate to be used, which can affect the configuration of the electrical device. There is also a risk of damage to the electrical device prior to and during installation and trim-up of the dry wall. In such cases the installed electrical device may have to be replaced by a substitute device, which is a costly process. Attempts have been made to solve some of these problems by using adjustable-depth mud rings and junction boxes, as described for example, in U.S. Pat. Nos. 7,572,977, 7,531,743, 7,468,486, 7,189,928, 6,820,760, and 5,931,325. However, the adjustment of these components typically requires the use of multiple threaded screws, the manipulation of which is inconvenient and time-consuming. Moreover, the adjustability of these components does not address all of the problems arising from last-minute design changes and/or a substantial delay between the time the electrical devices are installed and the time they are actually ready to use, nor the risk of damage to the electrical device prior to completion of the drywall installation and trim-up process.